When it comes to advice, we prefer the intuitive.
Rules of thumb are best when shaped like thumbs.
As a result, we are provided with many thumb-shaped things, and told they are rules.
Beginning in the 1960s, a misinterpretation of nutrition studies led a coalition of researchers to assert that dietary fat caused fat to accumulate on the body and in the bloodstream. Makes sense, we concluded, that ingesting fat makes one fatter.
It took nearly fifty years for better thinkers to dismantle this mistaken narrative.
“You are what you eat,” they told us.
Take caution around thumb-shaped things.